So...this was purchased as an engine donor for a YSR project. Popular opinion is that it should be brought back to roadworthiness.
I should have taken pictures of it before we pulled it down. It was on a shelf about 4.5' off the ground. Just tall enough to have motorcycles under it and on top of it. When I first met my friend the bikes on top were 2 Montessa's, a Saracin, Yamaha DT250 (GYT kit, built to Kenny Roberts specs), 1974 Yamaha DT100A, TZ250 with 350 cylinders and pistons (original parts are in the shop), and a TA125. Sorry don't know the years of the Montessa's, Saracin, DT250, TZ or TA. The TZ has been sold, took less than a week after we pulled it down and took pics. The DT100A is obviously the one in the title of the post. The rest are up for grabs. Make a (reasonable) offer. Shipping is from Hawaii.
I've attached pics of the DT100A as it was when I brought it home, as well as pics with missing parts that were found in the shop installed. The ignition and left hand switch aren't correct but I can rewire to work.
The bike was well abused before my friend rescued it. Just look at the pic of the oil pump side and you'll get an idea of the flywheel/magneto side. As far as I can tell the left hand flywheel and countershaft sprocket covers had been removed to fit a shift lever not meant for the motorcycle. The shifter wouldn't fit after I put the covers on...
I have the lenses for the front blinkers, the rear blinkers, taillight, and headlight. As of right now I haven't found the oil tank or headlight ears. A stock exhaust would be nicer, but not necessary.
Pic of the left side...
I just love the look of those 70s dirtbikes. Brand or size doesn't matter. DT50 or XL350, they all look great. Until the triangular tanks became the norm....
Yep.. definitely a cool bike.. I have a 75 DT100 in my barn I'll get to one day I hope.
^^^^
Nice, and you have more to start with :)
Took the carb apart today. It's in amazing shape considering it's sat for at least 20 years. That's when my friend bought the building and started moving things in. The shape the motorcycle was in tells me it probably sat for years before my friend bought it. In any case the carb had some sediment in it, but no corrosions or pitting on the inside, or outside for that matter. Probably because they were running premix. There was still oil residue inside so everything was still lubed.
Anyone have experience with an oil pump that's been disconnected? I'm wondering if it will still work after having had both lines disconnected. If it had been me I probably would have removed everything, or at the very least left the oil feed from the tank and plugged it, and left the banjo to the cylinder alone. I can probably find another in the shop but if this one is salvageable that would be much easier. Do I just run oil to the pump and see if it pumps? I know there's a banjo bolt in the box of old oil pumps so if it's easier to just swap it out I can go that route, if I can find the correct pump.
If you are interested in upgrading I know I have a stock 1974 MX100 head, might even have a stock MX100 cylinder but would have to make sure. We have experience with the 74/75 MX100. Jemco who was in TX and now new owner in KY made an excellent pipe for them.
Quote from: John Ritter on April 05, 2021, 09:37:09 AM
If you are interested in upgrading I know I have a stock 1974 MX100 head, might even have a stock MX100 cylinder but would have to make sure. We have experience with the 74/75 MX100. Jemco who was in TX and now new owner in KY made an excellent pipe for them.
John,
Who is the new owner of Jemco and is it still call the same name?
i had a custom pipe made for my Cr years ago by them.. yes good stuff.
Never mind John. I just found them on the web.
What would the benefit be of changing to an MX100 cylinder and head? Does the cylinder support the oil pump? If I spend the time and money to bring this project back to ride on the streetl I don't want to run premix.
Thanks for the info regarding exhaust pipes. If I can get everything to work (oil injection, fit the electronics necessary for street use, etc.) with the pipe that's on it I'll keep it. If not I'll think about what I want to do about exhaust. I have added the JEMCO website to my favorites as they might come in handy for other projects.
A complete electronic ignition kit is available for this motorcycle; HPI part number 210k072 (part number is from HPI, I emailed them directly). treatland.tv can bring it in, $250 shipped to Hawaii. May be cheaper to the States. Once I have an idea of what's necessary and the costs to get it back on the street I'll decide if it's worth it or not.
Quote from: Diablo007 on April 08, 2021, 02:36:36 AM
A complete electronic ignition kit is available for this motorcycle; HPI part number 210k072 (part number is from HPI, I emailed them directly). treatland.tv can bring it in, $250 shipped to Hawaii. May be cheaper to the States. Once I have an idea of what's necessary and the costs to get it back on the street I'll decide if it's worth it or not.
The early 100cc Yamaha enduros are getting a lot of attention over the last few years. There is a FB group that is dedicated to them that you may like. I have besides the one I shared above a couple more. A 72 & a 73 LT. I hope you get yours back in shape.
@soonerbillz
We also have a '74 DT125A that is almost completely stock. Found in the same friend's shop. That is by far my favorite of the motorcycles we have now. It starts the day on a good note (pun intended) and no matter how the work day went I smile on the way home :D
Here are some pics from the day I was finally allowed to pull it out, give it a quick clean, and take pics.
Quote from: Diablo007 on April 05, 2021, 03:17:38 AM
^^^^
Nice, and you have more to start with :)
Took the carb apart today. It's in amazing shape considering it's sat for at least 20 years. That's when my friend bought the building and started moving things in. The shape the motorcycle was in tells me it probably sat for years before my friend bought it. In any case the carb had some sediment in it, but no corrosions or pitting on the inside, or outside for that matter. Probably because they were running premix. There was still oil residue inside so everything was still lubed.
Anyone have experience with an oil pump that's been disconnected? I'm wondering if it will still work after having had both lines disconnected. If it had been me I probably would have removed everything, or at the very least left the oil feed from the tank and plugged it, and left the banjo to the cylinder alone. I can probably find another in the shop but if this one is salvageable that would be much easier. Do I just run oil to the pump and see if it pumps? I know there's a banjo bolt in the box of old oil pumps so if it's easier to just swap it out I can go that route, if I can find the correct pump.
There is a fellow on FB called "Yamaha Enduro". The fellow is a expert in these bikes and if you send the pump to him he will return it to you like brand new. Plus he also stocks lots of other enduro parts and stuff.
Thanks for the info!
Found a NOS flywheel in the shop yesterday. Shows some age but it's in much better shape than the one the bike had originally. The only difference I can find is the original has what appears to be 'D-1' stamp while the one I found in the shop has a stamp of 'E-12'. The rest of the markings are the same.
I've attached pictures of the original and the NOS one after it was cleaned up. Thinking I'll hold off on ordering the HPI ignition for now.
Also thinking about running DT125 forks as there are more options regarding upgrades.
HPI ignition arrived and I finally had time to install it. Plate and rotor installed easily. Had to space the coil away from the frame as it was hitting. Used the mount sent with the kit and a couple of washers. I'll look for some spacers, or make them later. Haven't had time to time the ignition yet, I'll post about it when I do. I'm really impressed with the quality. The only thing not included with the kit was the plug cap. I ordered the kit through treatland.tv. They're pre-sale support was amazing. This was my first kit of this type. They answered all of my questions and helped me figure out everything I needed to convert the system from 6V to 12V. May sound easy to some of you, but I had concerns about what type of regulator/rectifier to use and how to wire it. They pointed me to the correct unit, which they carry, and the instructions for wiring it. I haven't wired or tested it, but with the quality of service they've provided so far I'm confident it will work. Looking forward to converting the system to 12V.
Kit didn't come with a plug cap...should I use a cap with a resistor or not?
Glad it is going well, I'll be following to see how it runs, it may encourage me to get mine running and swap it in my YSR.
Found an NOS steering lock in the shop and decided to install it. Realized the lock in the motorcycle didn't just 'pop' out when the face plate was removed. Looked at the NOS one and realized it had to pick the lock to remove it. Took me longer to fashion the lock picks than to pick the lock. Make a note of that; if the steering lock was that easy to pick the ignitions will be just as easy. Though with the ignition just cut the ground wire...
Had to relocate the CDI to get things to fit. Timed and fired up the engine. Awesome!!! Probably wishful thinking but it sounded peppy'er.
OK, updates are a little out of order. I did fit the oil tank and bleed the system before firing up the engine. Some pics are during fitment but not a lot changed between the fitment and the final install... Oil tank was found in the shop with a pair of 'Nimrod' hubcaps. Yes, 'Nimrod' hubcaps. Google 'Nimrod camper'. No idea how they made it to Hawaii. I have no idea what the oil tank came from but it looks as cool as I hoped it would. Was originally going to use it on a minibike but this is much better.
I still have to fit the wiring harness and connect the 12V regulator rectifier. I'm hoping the capacitor I picked up at a local electronics supply shop works as planned as I don't have much space. A battery is definitely not going to fit.
Regarding the plug cap; emailed Treatland as the instructions didn't specify resistor or non-resistor. Treatland seemed to thing the instructions said non-resistor so that's what's currently installed. I'll post regarding that if I run into problems.
Current parts needed/wanted:
Gas cap and lock; anything for a '74' - 75' DT100 - DT 350 should work. PM me if you have parts you're willing to sell.
Top and bottom triples for a DT125A or equivalent. I have forks left over from another project, just need the triples. Not only are the fork tubes cheaper they offer more in springs and such.
Just so happens I just picked up one of these in similar condition for a YSR swap and have been meaning to list up the rest of the machine here. Think mine is 74 as well, greenish gold? Goldish green? Cant remember, we took it apart after we got it sparking and I left most of it in my buddys shop. Thanks for the motivational thread, GL with the build, I thought about it but I do like the YSR.
I should have whatever you need and many of the parts are in good condition, I'll make sure my email is good here and I may be able to get pics et. al. soon, parts coming for a pair of Vespas saturday and the YSR is next in line. Low, low prices for the 2SW peeps, I rarely get around to selling on Ebay, and things just go in boxes.
Quote from: Clem710 on July 16, 2021, 01:34:26 AM
Just so happens I just picked up one of these in similar condition for a YSR swap and have been meaning to list up the rest of the machine here. Think mine is 74 as well, greenish gold? Goldish green? Cant remember, we took it apart after we got it sparking and I left most of it in my buddys shop. Thanks for the motivational thread, GL with the build, I thought about it but I do like the YSR.
I should have whatever you need and many of the parts are in good condition, I'll make sure my email is good here and I may be able to get pics et. al. soon, parts coming for a pair of Vespas saturday and the YSR is next in line. Low, low prices for the 2SW peeps, I rarely get around to selling on Ebay, and things just go in boxes.
Nice, Ill be interested when you get to the YSR swap, I also recently picked up one of these motor to swap into my YSR but that project will be down the road as my YSR is still running pretty good with the stock motor, I figure I will run it till it blows up.
@dg8493; I in pretty much the same situation with the YSR's. Both run so there's no need for an engine swap at this point. The bike was pretty complete so I decided to go with popular opinion and get it on the street again. Once I have everything ironed out I'll go about trying to get the title. I have the paperwork for the Vermont title (thanks to a forum member for adding to the paperwork and info I had already found). There's also a way to stand before a judge in civil court here and petition for a title. Cost is about the same either way. I have time to think about it.
@Clem710; thanks for the reply. I'll get an email off to you, or at least a PM. I'm in Hawaii, so flat rate envelopes and boxes are the best way to go.
@Clem710: PM sent, thanks
HPI ignition works fine. Hooked up the Trail Tech TT150 regulator/rectifier per the instructions on treatland's website:
Black - Ground (- side or ground)
Red - Capacitor/Battery and lights (+ side)
Red/Yellow - Not used
Yellow 1 - input AC current coming from Stator
Yellow 2 - Also Ground
Hooked up to a 35V - 6800mF capacitor. Output was roughly 14.40V. Capacitor was still over 13.60V about 2 hours after disconnecting from system. Capacitor was picked up from a local electronics parts shop for about $7.00.
Capacitor is installed in the 6V battery from my YSR50 that was bad. I cut the top off the battery and gutted the insides, then soldered leads to the terminals, then soldered the leads to the capacitor, (+) to (+) and (-) to (-). Still need to epoxy the top back to the bottom of the battery. Idea is to keep the YSR looking stock but not have to worry about batteries going bad anymore. Pics attached. Need to drain capacitor before moving to the YSR. I have a capacitor somewhere for the DT100A that will be installed without a case as space is limited.